Electric motors and method of manufacturing and operating same

ABSTRACT

Motor has outboard switch compartment with components therein such as a capacitor, thermal protector, terminal board, motor circuit controlling switch assembly, a manual switch, a thermal plastic molded cover for the compartment fastened with axially directed screws, and an optional rain shroud positively positioned on the end shield. The switch assembly is designed to have accurate contact alignment which will be maintained over the life of the switch; a wiping action of the contacts; a high amount of contact travel in terms of percentage of switch actuator travel; protected contact blade arms; and a multiple height mounting feature which assures a more optimum location of the switch at final assembly with respect to the location of the switch operating mechanism. Switch arms are essentially parallel and have contacts positioned directly in line with the actuating line of a switch actuator and an operating mechanism. A switch arm support is a molded synthetic material housing which, with a synthetic material molded switch actuator, provide precise and accurate preloading of the contact arms. Non-stick actuator features are included. Also included is a novel cover attaching approach and method, as well as switch assembly variable height mounting structure means and methods.

BACKGROUND OF THE INVENTION

The present invention relates generally to electric motors, and, moreparticularly, to motors of the type wherein the energization of motorwindings are controlled by switch mechanisms carried on the motor whichare actuated by axially movable switch actuating members; to motors ofthe type that are to be exposed to moisture such as, for example,moisture conditions encountered in outdoor environments; to motorshaving what are known in the art as outboard switch or accessory devicecompartments; and to motors wherein it is desirable to provide amotor-carried, externally-accessible switch for determining theoperational mode or condition of such motor.

As will be understood by persons of ordinary skill in the art, singlephase induction motors may be of many different types. Thus, there areresistance start, reactor start, capacitor start, permanent splitcapacitor, and capacitor start-capacitor run motors, to name but a few.These different types of motors are characterized by differentspeed-torque characteristics, and of course are capable of beingdesigned to have different theoretical maximum efficiencies. For manyapplications, and especially those where high starting torque isrequired, it is necessary for part of the windings in the motor to bedesigned and arranged to be an auxiliary or starting winding which isenergized during initial excitation of the motor but which isde-energized as the motor comes up to a predetermined speed.

One particular reference work that describes motor characteristics andgives specific application information regarding different motors is theC. G. Veinott book entitled, "Fractional and Subfractional HorsepowerElectric Motors", published by the McGraw-Hill Book Company. For moreinformation on this subject, the reader is directed, for example, to thethird edition of the Veinott book which was copyrighted in 1970 byMcGraw-Hill.

In many applications, it is known to use a centrifugally or otherwiseactuated switch assembly for de-energizing the auxiliary or startingwinding as the motor comes up to speed, and it is desirable to optimizesuch assemblies in terms of material content, assembly cost, andreliability. Some problems with some switch assembly designs that havebeen used heretofore, are believed to have been associated with acondition wherein the switch contacts have been "open" to theirenvironment and subject to damage, or to lodging of foreign material onor about such contacts. Another continuing concern for all types ofmotor circuit controlling switches is the question of accessibility orserviceability of such switches, as well as the cost associated withreplacing such switches. It thus also would be desirable to provide anew and improved switch of non-complex design which is reliable inoperation.

In switches of the type here contemplated, the long term maintenance ofdesired dimensional relationships of different switch parts andcomponents is important, in order that desired switch actioncharacteristics result, such as: good contact wiping action; contactself-cleaning action; controlled and limited lost motion relative travelof two or more switch parts; reliable switch action notwithstandingdimensional tolerance accummulations; collinear relationship of contactsand actuator line of travel; weld breaking action; and near-parallelrelationship of two contacts.

Accordingly, one of the objects of the present invention is to provide anew and improved switch which is simple in design, is capable of simpleinstallation to provide good contact wiping action, self-cleaningcharacteristics, and which does not require adjustment over the life ofthe switch.

Another object of the invention is to provide a new and improved motorcircuit controlling switch having limited and controlled lost motiontravel between the switch actuator and a switch contact itself, andimproved control of the switching action.

Still another object of the present invention is to provide a new andimproved switch wherein such switch may be readily mounted to provide anoptimum switching action notwithstanding an accummulation of dimensionaltolerances of other motor parts.

Other objects of the present invention are to provide a switch assemblywherein: switch contact faces can act in essentially a parallelcondition; switch contacts are positioned in close proximity to theswitch mechanism actuating line; spring return forces are applied onactuator driven mechanisms to limit upset reactions and switch sticking;switch contact alignment is positively established and maintained;wherein provisions are made for a weld breaking action during movementof the switch arms; potential for sticking as a result of dirt and dustis reduced; and switch blades or arms and contacts are encased in orderto provide protection for such elements.

In some applications, and especially those applications of motors usedto drive pumps such as jet pumps or swimming pool pumps, circuitcontrolling switches are mounted outboard of one of the motor end framesto facilitate access thereto. In many pump applications, there may beconcern regarding moisture, and it is desirable, e.g., in verticalapplications, to provide rain shrouds to prevent rain from enteringmotor ventilation openings. It thus is another object of the presentinvention to provide a new and improved rain shroud arrangement which isa single piece which can be interfitted in a positive manner with otherparts of a motor and yet wherein the rain shroud itself does not causewater to be trapped inside the outboard switch compartment. It is alsoan object of the invention to provide a new and improved cover for anoutboard switch compartment, as well as means for ensuring drainage ofmoisture from within such compartment when the motor is positioned forhorizontal shaft applications.

Also in some applications, one of which may be, e.g., a swimming poolpump application, it is desirable to have a manually selectable twospeed motor. An object of the present invention is to provide a motorhaving an outboard switch compartment arranged to accommodate therein amanually selectable switch, a capacitor, a thermal protector, and astarting switch.

SUMMARY OF THE INVENTION

In carrying out the above and other objects of the invention, in onepreferred form thereof, I provide a new and improved motor having anoutboard switch compartment with a number of components arranged anddisposed therein. Such components may include, for example, a startingcapacitor, a thermal protector, a terminal board and motor circuitcontrolling switch assembly (e.g., a starting switch assembly), and amanually actuable switch. In a preferred form, a starting switchassembly is utilized which includes not only a switch assembly per sebut also a terminal board and wherein the motor circuit controllingswitch may be adapted to control either a single speed or two speedmotor.

In accordance with other aspects of the invention, I provide a thermalplastic molded cover for the outboard switch compartment whichpreferably is fastened to the motor with axially directed mountingscrews.

In accordance with still other features of the present invention, I haveprovided a new and improved thermal plastic rain guard or shroud whichmay be assembled with a slip fit over an end shield and captured by theswitch compartment cover. Preferably, means are utilized to positivelyposition the rain shroud on the end shield.

In accordance with still other inventive features, a new and improvedswitching mechanism is provided which is designed for a high level ofquality and reliability by having accurate contact alignment which willbe maintained over the life of the switch; a wiping action of thecontacts; a high amount of contact travel in terms of percentage ofswitch actuator travel; protected contact blade arms; and a multipleheight mounting feature which assures a more optimum location of theswitch at final assembly with respect to the location of the switchoperating mechanism.

Switches embodying inventive features include essentially parallel,i.e., overlying switch arms having contacts thereon positioned directlyin line with the actuating line of a switch actuator. Moreover, at leasttwo of such switch arms are carried by a switch arm support thatpreferably is in the form of a molded synthetic material housing whichboth protects such arms and maintains the parallel alignment of sucharms. A synthetic material molded switch actuator and molded switch armmounting structure provide precise and accurate preloading of thecontact arms while at least one of the contact arms in turn cooperatesto ensure that a molded switch actuator is urged toward a switchoperating mechanism when the motor is stopped. Still other preferredfeatures include means built into the switch assembly to control thecontact gap and provide weld breaking action, means for guiding anactuator relative to the actuator support that also minimize potentialfor sticking and binding; and means for variable level or heightmounting of a switch assembly.

The subject matter which I regard as my invention is set forth in theappended claims. The invention itself, however, together with furtherobjects and advantages thereof may be better understood by referring tothe following more detailed description taken in conjunction with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vertically arranged motor embodyingthe present invention in one preferred form thereof;

FIG. 2 is a perspective view, with parts removed, of a horizontallydisposed motor embodying other features of the present invention;

FIG. 3 is a plan view of the motor shown in FIG. 1, with parts removedtherefrom;

FIG. 4 is a cross-sectional view, with parts removed, looking in thedirection of arrows 4--4 in FIG. 3;

FIG. 5 is a fragment of a view looking in the direction of arrows 5--5in FIG. 3;

FIG. 6 is a view fragment looking in the direction of arrows 6--6 inFIG. 3;

FIG. 7 is a cross-sectional view, with parts removed and parts brokenaway, looking in the direction of arrows 7--7 in FIG. 3;

FIG. 8 is a view corresponding to FIG. 7 except that it shows thecompartment cover in place on the motor end frame;

FIG. 9 is a plan view of the rain shroud shown in assembled relationshipwith the motor in FIG. 1;

FIG. 10 is a cross-sectional view taken in the direction of arrows10--10 in FIG. 9;

FIG. 11 is a cross-sectional view taken in the direction of arrows11--11 in FIG. 9;

FIG. 12 is a cross-sectional view taken in the direction of arrows12--12 in FIG. 9;

FIG. 13 is a detail showing the assembled relationship of the rainshroud of FIG. 9, the compartment cover best shown in FIG. 1; the motorshell, and the motor end shield which accommodates the rain shroud;

FIG. 14 is an enlarged perspective view, with parts broken away, of partof the molded portion of the switch assemblies shown in FIGS. 2, 3, and15;

FIG. 15 is an end view looking into the end of the motor shown in FIG.14;

FIG. 16 is a detailed view of the switch and terminal board shown inFIG. 15;

FIG. 17 is a view taken in the direction of arrows 17--17 in FIG. 16;

FIG. 18 is a view substantially similar to FIG. 16 except that itillustrates a modified mounting position (i.e., height) of the switchand terminal board with respect to mounting posts on the end frame;

FIG. 19 is a view taken in the direction of arrows 19--19 in FIG. 18;

FIG. 20 is an enlarged view of a portion of the switch shown in FIGS. 16and 17;

FIG. 21 is a cross-sectioonal view taken in the direction of arrows21--21 in FIG. 20:

FIG. 22 is a view of a portion of the structure shown in FIG. 21 butwith the switch arms and contacts in a different position due toactuation of the switch plunger or actuator;

FIG. 23 is an enlarged view of a portion of the switch mechanism shownin FIG. 3;

FIG. 24 is a cross-sectional view taken in the direction of arrows24--24 in FIG. 23;

FIG. 25 is a view showing a portion of the mechanism of FIG. 24 with theswitch actuator in an intermediate actuating position;

FIG. 26 is a view of the same structure shown in FIG. 25 but wherein theswitch actuator has travelled further so that two pairs of contacts havebeen closed;

FIG. 27 is a connection diagram for motors utilizing the switchingarrangement shown in FIGS. 15 and 16;

FIG. 28 is a connection diagram for motors using the switchingarrangement shown in FIGS. 3 and 23;

FIG. 29 is a view taken in the direction of arrows 29--29 in FIG. 18 andproviding a typical representation of the multiple mounting surfacetechnique used in switch assemblies illustrated in FIGS. 16 and 23;

FIG. 30 is a view taken in the direction of arrows 30--30 in FIG. 29;

FIG. 31 is an enlarged view illustrating the mounting of a manuallyselectable switch in motors embodying the present invention;

FIG. 32 is an enlarged perspective view of the switch actuator orplunger that forms part of the switch assemblies shown in FIGS. 15--28;and

FIG. 33 is a cross-sectional view through part of the motor covershowing a fastening scheme employed in preferred embodiments of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference now to the drawings and with particular reference toFIGS. 1 and 2, the structure shown will be described with particularemphasis being placed upon the new and useful features and parts.

FIG. 1 illustrates a motor 40 arranged in what is commonly referred toas a vertical shaft down position. As will be understood, the shaft 41projecting from the motor will be coupled with a pump impeller or anyother load that is to be driven by the motor. The motor 40 includes theshell 42 having upper vent holes 43 therein, an upper end frame which ishidden from view in FIG. 1 by a rain or drip shroud 44, and a lower endframe 46. The lower end frame includes a number of internally threadedbosses 47 by means of which the motor 40 may be assembled with a pumpassembly.

Also visible in FIG. 1 is a novel switch compartment cover 48 which isfastened to the upper end frame by means of a pair of axially orientedscrew fasteners 49, an electrical conduit fitting 51 threaded into atapped hole 52 (see FIG. 2) of the upper end frame, and a windingenergization control switch boot 53 (best seen in FIG. 31).

The rain shroud 44 is held in assembled relationship as part of thecomplete motor 40 by means of the cover 48, all as will be explained inmore detail. Thus, separate fastening means are not required for holdingthe rain shroud on the motor. Moreover, for applications where a rainshroud is neither needed nor desired, the shroud simply can be dispensedwith and in such an event, a motor arrangement as shown in FIG. 2 willresult where the rain shroud has in fact been dispensed with.

Referring now to FIG. 2, the motor 54 shown is substantially the same asthe motor 40, with the exception that it is a single speed rather than atwo speed motor, it does not include a rain shroud, and a speed orenergization selection switch 53 is not included. Because of this, thecover 56 is slightly different from the cover 48 in that no provision ismade for a switch which would protrude therefrom. Such a switch may beprovided when the motor is to be operable at two differnet speeds, orwhen it is desired to have a line disconnecting switch at the motor.

A manually operable switch, in the form of a toggle switch, is shown at57 in FIGS. 3 and 31 where it will be seen that the switch is trapped bymeans of a pair of nuts 58 on a switch bracket 59 which in turn isfastened to the end frame 61 by means of a pair of self tapping screws62. The bracket 59 is dimensioned so that when the cover 48 is placed onthe motor 40, the recessed surface 63 will fit about exposed threads onthe switch body. The rubber boot 53, having a threaded nut moldedtherein, then is threaded onto the switch to provide a waterproofarrangement.

With reference now to FIG. 3, the aluminum die cast end frame 61 (as isthe case also with the end frame 64 shown in FIG. 2) is fastened to theopposite end frame by means of clamp bolts 66 which pass through holes67 (see FIG. 4) that are provided in reinforcing bosses 68 which aremolded as unitary parts of the end frame.

Also revealed in FIG. 3 is a two speed switch assembly generally denotedby the reference numeral 69 which is mounted to the end frame by meansof three self tapping screws 71. The switch portion of the switchassembly 69 is illustrated in detail in FIGS. 23-26 and a detaileddiscussion of such assembly will be provided in conjunction with adiscussion of such figures. The terminal block portion of the switchassembly 69, on the other hand, is essentially the same as the terminalblock portion of the single speed switch assembly 72 illustrated indetail in FIGS. 16-19, 29, and 30. Because of this, a description of theterminal block and mounting portion of the switch assembly 69 will bedescribed in detail in conjunction with the terminal block portion ofthe switch assembly 72.

FIG. 3 further reveals the conduit fitting mounting leg 73, groundingscrew 74, centrifugal switch actuating or operating mechanism 76, astart capacitor 77, and a pair of cast bosses 78, and cast bosses 79,81, and 82. The bosses 78 surround tapped holes 83 which accommodateaxially directed screw fasteners that are used to secure the cover 48 tothe end frame 61. The boss 79, on the other hand, has a hole therein inwhich a self tapping screw 86 may be fastened to hold a capacitor clamp87 in place, which of course holds the capacitor 77 in place on the endframe. Underlying the capacitor 77 and holding the capacitor in spacedrelation to the end shield are four cast bosses or capacitor standofflegs 88, two of which may be best seen in FIG. 2.

At this point, it should be noted that, although the end shields 61 and74 are different, due to the provision of holes which are used to mounta manually operable switch, the end shields are otherwise identical, andthus like reference numerals have been used to denote like parts andportions of such end frames. Furthermore, in order to simplify thedrawings and avoid confusion, lead wires and jumper leads have not beenshown in any of the views. However, persons skilled in the art willunderstand that lead wires 91 and appropriate jumper wires interconnectthe capacitor 77, terminals on the terminal block portion of the switchassembly, and thermal protectors, such as the protector 92 (see FIG.2)--assuming such a protector is provided. Thus such wires areappropriately interconnected before the cover 48 or cover 46 is placedon the motor. The appropriate connection of such wires and jumpers willbe apparent from FIGS. 27 and 28, and will be described below inconjunction with a discussion of the FIG. 27 and FIG. 28 wiringdiagrams.

Continuing now with a description of FIG. 3, it will be noted that theboss 81 is provided with a centrally located hole while the boss 82 isprovided with a centrally located pin 80 projecting upwardly therefromas viewed in FIG. 3. The use and function of the bosses 81 and 82 inconjunction with mounting the thermal protector 92 of FIG. 2 will bebest appreciated by also considering FIG. 15. Thus, one ear of aprotector 92 is caught on pin 80, while the other ear of the protectoris fastened to boss 81 by means of a self-tapping screw which isthreaded into the hole 85 which is cast in the boss 81. By this means,the protector 92 may be positively mounted quickly and yet with a singlemounting screw.

Considering together FIGS. 3-8 and FIGS. 9-13, the interrelationship ofthe shroud 44, end shield 61, cover 48, and motor shell 42 will bedescribed in detail. With reference first to FIG. 13, it will beunderstood that the end shield 61 includes a rabbet surface 93 alongwhich the cover 48 fits. Also formed in the end shield are a number ofnotches generally denoted by the reference numeral 94 which accommodatetabs 96 (see FIG. 9) formed on the shroud 44. Thus, in order to assemblethe shroud with the motor, the shroud is slipped along the rabbetsurface of the end shield 61 so that the tabs 96 thereon are received inthe notches 94. Subsequent assembly of the plastic cover 48 traps andholds the shroud 44 in place.

It will be seen from FIG. 9 that four tabs 96 are provided on the shroud44. However, the number of tabs provided is not critical, so long as asufficient number are provided to securely hold the shroud in place andprevent it from being inadvertently separated or torn from a motor towhich it is attached.

Preferably, the shroud is molded from any suitable engineering plasticmaterial. In actual reductions to practice of the invention, Noryl®HS2000 phenylene oxide resin purchased from the General Electric Companywas used for molding the shroud 44.

FIG. 10 represents a "typical" cross-section of the shroud 44. However,in order to provide added strength and rigidity to the shroud, a numberof ribs 96 (see FIG. 12) are molded into the shroud at a number ofspaced apart locations. It also will be noted that two notches areprovided in the shroud, the first one being generally identified at 98to provide clearance for the conduit leg portion of the end shield, anda second notch 99 (see FIG. 11) is provided to accommodate an oil fillertube plug 101 carried by the end frame (see FIGS. 2 and 3).

FIGS. 4 and 5 reveal that the notches 94 are relatively small. Forexample, suitable results have been obtained when the notches wereapproximately 0.375 inches wide (measured across FIG. 5) and about 0.060inches deep (measured across FIG. 4).

An additional notch 102 will also be noted in the rabbet surface 93 (seeFIGS. 3 and 6). The notch 102 is wider than the notches 94 and has beenmade, in actual reductions to practice, to be approximately 0.500 incheswide (across FIG. 6) and approximately 0.035 inches deep. Moreover, thisnotch is located as shown in FIGS. 7 and 8 so that when a cover 48 or 56is positioned on the end frame, a labyrinth drain passage 103 will bedefined between the machined surface of the end shield and the switchcompartment cover. This labyrinth drain passage is of particular valueand use for horizontal shaft applications. In such applications, themotor is relatively positioned, as shown for example in FIG. 3, with theoil well filler cap 101 at the top of the motor and the drain notch 102located at the bottom of the motor. With this arrangement, any moisturethat might condense or otherwise occur inside the switch compartmentwill be able to readily drain out of the motor and yet the passagewaywill be sufficiently small to inhibit entry of insects.

The covers 48 and 56 preferably are molded plastic for reasons ofsimplicity, economy, corrosion resistance, general durability, andelectrical isolation. Although substantially any desired engineeringplastic material may be used, preferred embodiments have utilized Noryl®HS2000 thermoplastic material purchased from General Electric Company inmaking the covers 48 and 56.

With reference now to FIGS. 15-19, mounting of the switch assemblies 72and 69 will be explained. It will be noted from FIGS. 17 and 19 that thedie cast aluminum end frames have two mounting posts 104, 106 casttherein as well as a standoff post 105. As will be best appreciated froma review of FIGS. 18, 29, 17, and 19, the terminal board portion of theswitch assembly 72 is provided with a multiple mounting surface designand thus mounting surfaces 107 or 108 may be positioned on top of themounting posts 104, 106, and post 105. In the case of FIG. 17, mountingsurfaces 107 are resting on the top of the posts 104 and standoff. Onthe other hand, in the case of FIG. 19, mounting surfaces 108 areresting on the top of the posts and standoff. With an arrangement suchas that illustrated, it is possible to vary the height of the switchassembly above the top of the end frame as viewed in FIGS. 17 and 19.This is desirable for reasons that are explained hereinbelow. For themoment however, it is sufficient to note that assembly of a switchassembly 69 or 72 with an end frame can be readily accomplished with theassembly at different predetermined heights above the end shield indifferent motors simply by choosing to use mounting holes 110 (in whichcase surfaces 108 will rest upon end shield supporting surfaces) or byusing mounting holes 111 (in which case surfaces 107 will rest upon endshield supporting surfaces).

The provision of an elongated slot 109 facilitates assembly, and whereasrelatively short screws 71 are shown fastening the switch assemblies tothe mounting posts 104, 106, a relatively longer screw 100 is threadedinto the end frame.

The variable level or height mounting just described may be accomplishedto vary the height of the switch assembly 69 or 72, above the end framewithout having any affect on the interaction between the switchoperating mechanism and the switch assemblies 69, 72. The reason forthis is that the holes 110, 111 are located along an arc of a circlehaving its center at the centers of the switch contacts which areessentially co-incident with the point 113 along which acutating forcesare applied to the switch assembly. Similarly, the slot 109 has itscenter located along a circle that is concentric with the arc defined bythe centers of holes 110 and 111. Of course, the mounting posts orbosses 104, 106, and the holes therein lie along an arc congruent withthe arc that locates the centers of holes 110 and 111.

While two discrete steps have been illustrated such that mountingsurfaces 107, 108 result, it should be understood that three or moresurfaces could be provided to provide either a greater overall range ofmounting height adjustments or "finer" graduated adjustments. Moreover,while discrete steps have been shown and are preferred for providingvariable height mounting surfaces, it should be undertood that one couldprovide a smooth inclined plane mounting surface (along with slotsrather than discrete holes 110, 111) so that infinitely variablemounting heights could be provided within the range of heights affordedby the two ends of such inclined plane mounting surfaces.

Before leaving FIGS. 16-19, it is further noted that the variousterminals 116 and line terminals L1 and L2 are formed from conventionalelectrical brass material. On the other hand, the molded portions of theswitch assembly and terminal board which will now be described in evenmore detail, are preferably formed from any suitable engineeringplastic. In preferred forms, the switch assemblies illustrated anddescribed herein have been formed from Valox® 420 thermoplastic materialpurchased from the General Electric Company.

The molded portions of the switch assemblies and terminal boards 69, 72are virtually identical. Moreover, all of the parts utilized in theswitch assembly 72 (now to be described in detail) are also present inthe switch assembly 69 except for the fact that one of the switch armsin the switch assembly 69 is elongated as compared to its correspondingarm in the assembly 72.

It will be appreciated from a review of FIGS. 16 and 17, that the switchassembly 72 includes a terminal board portion which includes themounting surfaces previously described, an electrical isolation wall 117separating the terminals L1 and L2, and a reinforcing and protectingwall 118. Also included is a switch arm mounting section which is bestviewed in the upper portion of FIG. 16 and which portion furtherincludes a switch actuator retaining means. The arrangement of thesemeans will be better appreciated by referring to FIGS. 20-22 wherein 119generally denotes the switch arm supporting section and the referencenumeral 121 is used to denote a bore defining distal portion whichfunctions as an actuator retainer means and is illustrated in the formof a barrel.

Comparing FIGS. 20 and 21 for a moment, it will be seen that thesupporting section 119 includes a channel defined between a pair ofwalls 122 and a floor 123. Moreover, disposed within such channel is aswitch arm 124 which is fastened to the floor of the channel by means ofa rivet 126. The end of arm 124 is folded back upon itself asillustrated, and the extending double thickness portion thereof forms aspade terminal 116 for connection to a female connector. As will be seenfrom FIG. 21 the arm 124 carries a switch contact 127. Overlying theswitch arm 124 and within at least part of the previously mentionedchannel is a second switch arm 128 which carries a contact 129 at onelocation and which is folded upon itself to form a spade terminal 116,and fastened to the switch arm supporting section by a rivet 131. Sincethe connection of the switch arms, rivets, and molded substrates to oneanother by means of a rivet approach is known in the art, furtherdiscussion of such connections is not presented herein.

A perspective detail of the barrel 121 is presented in FIG. 14 and itwill be noted that the barrel includes front and rear slots 132, 133.With the switch arms shown in FIGS. 20-22, it will be appreciated thatboth of these arms project along the slot 132. Disposed within thebarrel 121 is an actuator 134 which is best shown in FIG. 32. Theacutator 134 includes front and rear slots 136, 137 respectively, twoupper flanges 138, and a force transmitting centrally disposed actuatingrib or switch arm driver 139.

As best revealed in FIG. 22, the actuator serves as a plunger having arelatively thick in cross-section (for wear purposes) bottom reactionwall that coacts with a switch mechanism, and side wall portions thatare somewhat less thick in cross-section. As will be appreciated fromFIGS. 20-22, the molded actuator and switch arm support jointlyestablish a maximum open contact gap between the contacts 127, 129.

When assembling the switch assembly 72, an actuator 134 is disposed inthe barrel 121 and the slots 136, 137 (of the actuator) are aligned withthe slots 132, 133 of the barrel 121. Thereafter, the contact and switchblade 124 are positioned in the channel defined by walls 122 and theswitch arm 124 is permanently secured to the floor 123 with the rivet126. When this is accomplished, the tension on the normally flat switcharm 124 holds the actuator 134 in place in the barrel 121.

With reference to FIG. 21, it will be noted that the difference inheight between the floor 124 and the top edge or surface 141 of the rib139 will determine the amount of preload that is placed upon the switcharm 124. This preferably is considered since the switch arm 124 providesthe restoring force to the actuator during switch operation. After theactuator, switch arm 124 and rivet 126 have all been assembled with theswitch supporting section 119, the second or upper switch arm 128 ispositioned along the slots 132, 133 of the barrel 121 and rivet 131 isused to attach the upper switch arm 128 to the switch arm supportingsection 119. An abutment surface 117 locates the free end of arm 128 soas to preload this arm. The amount of such preload is determined as willbe understood, by the mold cavity dimensions which determine therelative locations of surface 147 and the surface 130.

It will be noted that rib guides 142, which act as spacers, are moldedto project from the axially extending interior surface of barrel 121.The outer surface of actuator 134 rides along these ribs and the spacethus provided between the outer surface of actuator 134 and most of theinterior walls of barrel 121 helps assure that dust, dirt, or otherdebris will not cause sticking of the plunger or actuator 134 withinbarrel 121 and thus disturb reliable and consistent switch operation.

When the motor 54 (see FIG. 2) is not running, the conventionalcentrifugal mechanism 76 (see FIG. 15) will be positioned so that theactuating tongue 143 thereof (see FIG. 22) biases the actuator 134upwardly as best shown in FIG. 22. In this condition, the contacts 127and 129 are engaged with one another and power thus would be supplied toan auxiliary or starting winding when it is applied across lineterminals L1 and L2 of the switch assembly 72. It will be noted thatwhen the switch arms 128, 124 are in the deflected positions thereofshown in FIG. 2, there is a force exerted from both of such armsdownwardly against the acutator rib 139. Moreover, it will be noted thatwhen the switch arm 128 is in the position illustrated in FIG. 22, adistal portion 146 thereof is spaced from a blade stopping surface 147that is formed as part of the barrel 121. Then, when the motor 54 isenergized, as it comes up to speed, the centrifugal mechanism 76 will,with a snap action, pull the tongue 143 downwardly in the direction ofarrow 148 (see FIG. 22) a distance sufficient that actuator 134 will notcontact tongue 143 even when the flange 138 of the actuator is restingon the upper surface 149 of the barrel 121.

During motor operation, as the tongue 143 (see FIG. 22) snapsdownwardly, the switch arms 124 and 128 immediately snap the actuator134 downwardly. However, as the actuator 134 and switch arms 124, 128are moving, portion 146 of switch arm 128 impacts the switch armstopping surface 147 and the contact 127 carried by switch arm 124thereupon separates from the contact 129 so that they attain theirrelative positions thereof as viewed in FIG. 21.

It is desirable that plunger 134 and contact 127 travel as far aspossible during a switch breaking action since the tension or springforce tending to aid breaking is a function of and proportional to theamount of deflection of arm 124. Such deflection, in turn, is a functionof and proportional to the amount of travel of plunger 134. It will beappreciated that tongue 143 undergoes only a finite amount of travel forany given switch operating mechanism. However, with switches designed asshown herein, maximum utilization of the travel of the switch operatingmechanism is attained. Thus, the travel of plunger 134 can be, ifdesired, 100% of the travel of tongue 143. This desirable result occursbecause the movements of contacts 127, 129, plunger 134, and tongue 143are essentially collinear.

With reference now to the connection diagram illustrated in FIG. 27, theauxiliary winding 149 and main windings 151, 152 of motor 42 arenormally not energized when power is not supplied to line terminals L1and L2. However, at that instant in time, switch arms 128 and 124 of theswitch assembly 72 are positioned so that the contacts thereof areclosed. Thus, as soon as power is supplied to line terminals L1, L2,power will be supplied to the auxiliary winding 149 thorough capacitor77 and to both main windings 151, 152. Subsequently, when power issupplied to line terminals L1, L2, the motor 54 will start, come up tospeed, and the centrifugal switch actuating mechanism will cause theactuator 134 to move so that the contacts carried on contact arms 124,128 will separate, thus breaking the supply of power to the auxiliarywinding 149. However, main winding sections 151, 152 will continue toreceive power through the thermal protector 92 and the motor willcontinue to run. Later, when the motor is de-energized, the centrifugalmechanism will reset and the tongue 143 thereof will once again closethe switch in switch assembly 72.

It should be understood that the capacitor 77 has been shown in thewiring diagram of FIG. 27 and in other views in the drawings herein forpurposes of illustration. However, it should be understood that theswitch assembly 72 and switch assembly 96 may be used with types ofmotors that do not utilize start capacitors such as, for example,resistance split phase motors.

With reference now to FIGS. 23-26, it is noted that the molded portionsof the switch assembly 69 there shown are identical to the moldedportions of the switch assembly 72 shown in FIGS. 20-22 and the relativemovement and operation of such parts are also identical. However, in theswitch assembly 69, the lower or first switch arm 153 is longer than theswitch arm 124 of switch assembly 72. Moreover, the lower switch arm 153carries not only a first contact 127, which is arranged to engagecontact 129 on switch arm 128, but lower switch arm 153 also carries asecond contact 154. The extended portion of switch arm 153 passes alongthe notches or slots 137 and 133 previously described. Thus, as was thecase also with the switch arms in the switch assembly 72, the parallelalignment of the switch arms 153 and 128 in the switch assembly 69 aremaintained by means of the channel established by the walls 122 as wellas due to the fact that the switch arms pass along and are confined bythe notches 136, 137 of the actuator 134.

The switch assembly 69 further differs from the switch assembly 72 inthat a bifurcated third switch arm structure 156, carrying a contact 157is provided. The two legs of switch arm 156 straddle the other two armsand are attached to the switch arm supporting section 119 by means ofrivets 158 which pass through the holes 159 in the supporting section119. The rivets 158 may also fasten a terminal (not visible in FIG. 23)to the supporting section for connection to a lead wire. Alternatively,such wire may be welded or soldered directly to the end of the arm.

Attention is now directed to FIGS. 20 and 32 and the abutment posts 159that are molded as part of the barrel 121. These abutment posts or earsserve as stops for the switch arm 156 and limit downward travel ofswitch arm 156 when the actuator 134 moves downwardly to the "openswitch" position thereof. Operation of the switch assembly 69, uponmovement of the switch mechanism tongue 143 (see FIG. 26) is the same asdescribed in conjunction with the operation of switch assembly 72. Thus,with reference first to FIG. 26, prior to the time the motor 40 isenergized, both pairs of contacts 127, 129 and 154, 157 are closed.However, when the motor is energized and as it comes up to speed, themechanism tongue 143 snaps downwardly in the direction of arrow 148 asviewed in FIG. 26, with the result that the actuator 134 snaps throughthe position shown in FIG. 25 to the open switch position shown in FIG.24. With the arrangement illustrated in FIGS. 23-26, the switch arm 156contacts the abutment post 159 so that contacts 154 and 157 separatefrom one another with a weld breaking action and thereupon the distal orend portion 146 of the contact arm 128 contacts the blade stoppingsurface 147 of the barrel 121 whereupon further movement of the switcharm 128 is arrested and contacts 127 and 129 separate with a weldbreaking action. This same action also occurs with the structure shownin FIGS. 20-22.

With reference now to FIG. 28, a connection diagram for the switchassembly 69 in conjunction with motor 40 will be described. In thiscase, the motor 40 is a two speed motor capable of operation either attwo pole speed (3450 rpm) or four pole speed (1725 rpm). In FIG. 28, thetwo pole start winding 161 is connected to the switch arm 156 while thetwo pole main winding 162 is connected to the switch arm 128, whereasone side of the four pole main winding 163 is connected to lowermost,first switch arm 153. The other side of all three windings 161, 162, and163 are connected through a thermal protector, embedded in the windingend turns, to line terminal L2 and thus to one side of the line whenline power is supplied to terminals L1 and L2.

The four pole main winding 163 (which is connected to the switch arm153) is also connected, through a line 164, to the low speed terminal ofthe toggle switch 57. The high speed terminal of the toggle switch 57 onthe other hand is connected to the same blade terminal as the end of thetwo pole main winding 162--i.e., the terminal connected to switch arm128. For high speed operation, the toggle switch will be in the solidline position illustrated in FIG. 28. Thus, when power is supplied tothe line, line L1 is connected through the movable contactor of thetoggle switch 57 to the contact blade 128. At this instant in time, twopairs of contacts of the switch assembly 69 are closed as shown in FIG.26. Thus, power will be supplied at that instant to all three of thewindings 161, 162, and 163. However, as the motor comes up to speed,both contact pairs open as represented in FIG. 24 with the result thatneither the two pole auxiliary winding nor the four pole main windingare supplied power from the switch arm 128. Thus, the motor 40 will haveonly the two pole main winding 162 energized and it will operate at highspeed.

When the toggle switch 57 is switched to the low speed configuration, asrepresented by dashed lines in FIG. 28, power is supplied to lineterminal L1 and thence through line 164 to the four pole main winding163 as well as to the switch arm 153. Since the condition of the switchassembly 69 at starting is as shown in FIG. 26, power thus will besupplied from line L1 through the switch arm 153 and contact pairs shownin FIG. 26 through the switch arms 128 and 156 to both the two poleauxiliary winding and the two pole main winding. Thus, for low speedoperation the motor will start as a two pole high speed motor. However,as the motor comes up to speed, the contact pairs separate and theswitch assembly 69 is in the configuration as illustrated in FIG. 24. Atthis time the three switch arms 128, 153, and 156 are electricallyisolated from one another so that the two pole auxiliary winding and twopole main winding are no longer energized. Thus, the motor 40 willcontinue to run as a four pole, low speed motor.

With reference now to FIG. 33, the mode of attaching covers 48 and 56 tothe motors 40 and 54 will be described. It is believed that, heretofore,covers have been made of metallic material and fastened with radiallydirected screws. The arrangements shown herein, however, utilize axiallydirected screws which is more convenient in the field. Moreover,enlarged posts 201 resist the collapsing force resulting from tighteningthe screws 49. As will be seen from FIG. 33, provision is made toprevent the cover from being cracked or otherwise damaged by screw 49.Thus, the tapped hole 202 in the end frame is dimensioned so that screw49 will bottom out therein. The screw 49 and cover 48 are in turndimensioned so that the head of the screw and common steel washer 204,when considered alone, would not apply any compressive force on thecover even when the screw is bottomed in hole 202. However, limited,nondamaging compressive force, coupled with a water sealing effect isprovided by a compression washer 206 trapped between the steel washer204 and the cover 48, any suitable compression washer or elastomericmaterial may be used, and in an actual reduction to practice of theinvention, 50 durometer rubber having a nominal uncompressed thicknessof 0.100 of an inch was used. The dimensions of the hole 202, cover 48,screw 49, and washer 204 were such that the washer 206 was compressed toa thickness of about 0.045 of an inch; with the screw 49 beingdimensioned to a tolerance of plus or minus 0.010 of an inch.

In this manner, the plastic covers are protected from damage caused byovertightening of screws 48 and a water repelling seal about the screwsis provided by a single means--i.e., the compression washer.

Study of FIG. 33 will also reveal detents 209 molded in the internaldiameter of hole 202. When the screw 49 is placed in hole 202, it can bethreaded past detents 209. However, when the cover 48 is removed in thefield, the detents prevent screws 48 from falling out of the cover.

It should now be understood that I have described and shown numerouspreferred embodiments of new and novel motor constructions and operatingtechniques. Moreover, new and improved methods of assembling andadjusting switch assemblies have been described as well as new andimproved methods of assembling novel switch assembly components.

Accordingly, while I have now shown and described preferred andalternate forms of motors and assemblies therefor, as well as methodspertaining thereto, the disclosure contained herein should be construedas being exemplary, and the invention itself should be limited only bythe scope of the claims that are appended hereto and that form part ofthis disclosure.

I claim:
 1. In an electric motor winding energization controlling switchassembly comprising a switch arm support, at least two elongate switcharms supported thereon, and at least one contact carried by each of saidswitch arms, the improvement wherein: said support includes an elongatechannel, for accommodating and protecting at least one of said switcharms and further includes an open barrel retainer at one end thereof forreceiving a switch actuator; at least one of said switch arms is nestedwithin said elongate channel; the switch arm support includes a switcharm stop surface; one of said switch arms is supported for movement intoengagement with said stop surface; the assembly includes a cup shapedactuator disposed within said open barrel retainer; and said actuatorhas means for maintaining at least two of said switch arms in parallelalignment with one another.
 2. The invention of claim 1 wherein saidactuator includes a switch arm driver for engaging and deflecting atleast one of said switch arms.
 3. The invention of claim 2 wherein theactuator comprises a plunger having at least one sidewll portion and areaction wall for coacting with a switch operating mechanism; saidreaction wall being thicker in cross-section than said at least onesidewall portion.
 4. The invention of claim 1 wherein the actuatorincludes a flange; and the flange, at least one of the switch arms, andthe support interact to retain the actuator within said retainer.
 5. Theinvention of claim 4 wherein the actuator is a molded part, and thedimensions of the actuator and switch arm support establish a maximumopen contact gap between the contacts carried by the at least two switcharms.
 6. The invention of claim 1 wherein the molded switch arm supportincludes means for mounting the support at different elevations withrespect to a mounting of the surface motor.
 7. The invention of claim 6wherein the molded switch arm support includes a terminal block portion,and said means for mounting are disposed on the terminal block portion.8. The invention of claim 1 wherein the switch arm support and actuatorare molded synthetic material structures.
 9. In an electric motorwinding energization controlling switch assembly comprising a switch armsupport, at least two elongate switch arms supported thereon, and atleast one contact carried by each of said switch arms, the improvementwherein: said support includes an elongate channel for accommodating andprotecting at least one of said switch arms; at least one of said switcharms is nested within said elongate channel; said support includes aswitch arm stop surface and a switch actuator retainer; one of saidswitch arms is supported for movement into engagement with said stopsurface; the assembly includes an actuator disposed within saidretainer; said actuator has means for maintaining the at least twoswitch arms in parallel alignment with one another; said retainerdefines an opening within which said actuator is accommodated; andwherein at least one of the facing surfaces of the retainer and actuatoris provided with rib means for preventing broad based surface to surfacesliding contact along said opening and between said actuator andretainer.
 10. The invention of claim 9 wherein the switch arm supportincludes abutment surface means and switch arm mounting areas so that atleast one additional switch arm may be held thereby.
 11. The inventionof claim 10 wherein the assembly includes a third switch arm having acontact thereon and carried by the blade support; the actuator includesa driver that directly engages one of the switch arms; wherein theswitch arm engageable by the switch arm driver includes two spaced apartcontacts, a first one of which is aligned and engageable with a contacton a second switch arm, and the second of which is aligned andengageable with a contact on the third switch arm; and the switch armsupport includes means for limiting movement of the third switch arm.12. The invention of claim 11 wherein the third arm is a bifurcatedmember having a bight portion and two legs, and a contact is carried onthe bight portion thereof, and wherein both legs of the third arm arefastened to the support, thereby to assure alignment of the contact onthe third arm with the contact on the first arm, and wherein theactuator includes a guide notch which limits transverse movement of thesecond switch arm.